Voltage-regulator.



v F. comm. VOLTAGE BEGULLTOB. APPLIOA'IIOI FILED JAI. 5, 1907.

923,627. mama a 1, 19%.

thi lFltlE.

FRANK CONRAD, OF SWISSVA LE, PEVNSYLVANIAv ASSIGNUR 'l'l) WESTINGHOUSE-ELECTRIC &

MANUFACTURING (TOM PAN Y.

A (TORlOlL-VYTON OF PENNSYLVANIA.

VOLTAGE-RE GULATOR.

T all whom it may concern: Be it known that I, FRANK CONRAD, a l

citizen of the United States, and a resident of Swissvale, in the countyof Allegheny and I State of Pennsylvania, have invented a new 4 anduseful Improvement'in Voltage-Begin lators, of which the following is aspecification.

My invention relates to regulators that are adapted to be employed inconnection with electrical generators for causing the same to supplyconstant voltages to distributing cir cuits, and particularly to thosethat effect voltage regulation by adjusting the field strengths of theexciters for the generators.

The object of my invention is to provide a regulator of the characterindicated that shall be more effective in operation and more readilyapplicable to the adjustment of the field strengths of large eXcitersthan others heretofore employed.

Figure 1 of the accompanying drawing is a diagrammatic view of a systemthat enibodies my invention. Fig. 2 is a similar view of a modificationof the system shown in Fig. 1, and Fig. 3 is a diagram of a portion of asystem embodying still another modili-- cation of the invention.

An electrical circuit that comprises conductors 1 and 2, the voltage ofwhich it is desired to maintain substantially constant, is supplied froma generator 3, here indicated as adapted to supply alternating current,but replaceable, if desired, by a generator adapted to supply directcurrent. The generator 3 is provided with a field magnet winding 4 thatmay be energized by an ex-- citer generator having an armature 5 and amain field magnet winding 6 that is connected across the terminals ofthe armature 5, rheostats 7 a'nd 8 being placed in circuit with therespective field magnet windings 4 and 6 for manually adjusting theamounts of current that traverse the said windings. In the system shownin Fig. 1, the eXciter generator is also provided with two auxiliaryfield magnetwindings 9 and 10 that are connected, respectively, inseries with resistances 11. and 12, across the terminals ot'the armature5 of the exciter. The windings 9 and 10 preferably comprise equalnumbers Specification of Letters Patent.

Application filed January 5,

' tively, to terminals of the field magnet windof ampere turns that areless than are ampere turns of the main field magnet winding 6, I andthey are so connected in the circuit that the magnetizations causedthereby oppose Patented June 1, ieoe. 1907. Serial No. 350,969.

one of the windings (10) acts in conjunction with the main winding 6,while the other (9) acts in opposition to it. In practice, the fieldstrength of the main' winding 6 will ordinarily be so adjustedthatfunder the most usual conditions of operation, it-will provide justthe proper excitation for the exciter generator.

The resistances 11 and 12 that are in circuit with the auxiliary fieldmagnet windings 9 and 10 may be short-circuited by means of a deviceconnn-ising stationary contact terminals 13 and 14, that are connected,respec- 70 ings 9 and 10, and a movable contact'terminal 15 that isconnected to one terminal of the armature 5 and isad apted to bevibrated between, and into and out of engagement with, thestationaryterminals 13 and 14, by means of a lever 16. The lever 16 may be movedto its uppermost position, inorder to effect engagement of the contactterminals 14 and 15, by means of a spring 17, and downwardly against thetension oi the spring 17, in order to effect engagement of the contactterminals 13 and 15, by means of a magnet having a winding 18 oneterminal of which is connected to one terminal of the armature 5 and theother terminal of which is connected to a lever 19 that is provided witha contact ter minal 20. The lever 19 may be moved downwardly, againstthe tension of a'spring 21, by means of a magnet having a winding 22that is connected across the terminals 01' the armature 5, the operationof the lever 19 being, in this manner, caused to depend upon the voltageof the exciter generator. The circuit of magnet winding 18 is adapted tobe controlled by the'movement of the contact terminal into and out ofengagement with another contact terminal 23 upon alever 2 1 to which oneterminal of the armature 5 is connected. The position of the contact timminal 22 depends upon the relation of the forces that are exerted uponopposite ends of r the lever by means of a spring 25 and a-inag nethaving a winding 26 that is connected across the main circuit conductors1 and 2, the intensity of the magnetization exerted by 105 the winding26 depending upon the voltage of the main circui As has been pointedout, the mainficld magiiet winding 6 ol' the exciter generator allordsinst he ioiier evcitatioil therefor 11 under the most usual conditions,as regards the loadupon the main circuit 1--2 and, con

sequently, the average excitation afforded by the windings 9 and 10should be zero. This result is secured, in the present instance, bycausing the contact terminal 1 5 to be vibrated between the contactterminals 18 and 14 so as to make engagement alternately therewith forequal periods of time, the magnetizing effects 01' the windings 9 and 10being in this manner caused to predominate over each other alternately.In order to better understand the manner in which the contact terminal15 is vibrated into and out of engage ment with the contact terminals 13and 14h, let it be supposed that the contact terminals 20 and 23 are inclose proximity, but out ol' engagement. Since the circuit ol' themagnet winding 18 is interrup d, the spring 17 will move the contactterminal 15 into engagement with. stationary terminal 14. The resistance12 will thcnbe short-circuited and the auxiliary iield magnet winding 10will be more strongly energized than the winding 9 and will supplementthe magnetization ati'orded by the main iield n'iagnet winding 6. Thcexciter will then impress a higher voltage upon the field magnet winding4 of the generator 3 and thus cause a correspomling increase in thevoltage of the circuit 12. The increase of the exciter voltage causesthe magnet winding 22 to be more strongly energized and the contactterminal 20 will be moved into engagement with the terminal 23. At thesame time, the increase in the voltage of the circuit 12 may also causeastronger cnergization 01' the winding 26, and the contact terminal 28may thus be moved upwardly a slight amount to assist in ellcctingengagement of the contact terminals 20 and 23.

The. circuit of the magnet winding 18 is established by the engagementof the contact terminals 20 and 23 and the contact terminal 15 isthereupon moved downward into engagement with the stationary terminal13. The resistance 11 is in this manner short-circuited, and theauxiliary field magnet winding 9 predominates in its magnetization overthat of the winding 10 and detracts from the excitation afforded by themain field magnet winding 6. The voltage applied to the fieldmagnetwinding 4 of the main generator by Y thecxciter is thus reducedand a slight reduction in the voltage of the circuit 1--2 follows. Thereduction in the exciter voltage causes a corresponding reduction in them agnctization of the winding 22 and the spring 21 efi'ectsdisengagement of the contact terminals 20 and 23. At the same time thereduction in the voltage of the circuit 12 may also cause acorresponding reduction in the magnetization of the windings 26, and thespring 25 may assist in eflectmg disengagement of the contact terminals20 and 2 lithe voltage of the circuit 1-2 is decreased as, for instance,by a heavy load, the

magnetization of the winding 26 will be reduced and the contact terminal23 will be lowered by the action of the spring 25. Then,

'riods of time than with the stazation oi' the winding 9 willpredominate over that ol' the winding 10. An increase in the fieldstrength of the exciter generator is thus ell'ectcd which causes acorresponding increase in the voltage applied to the field magnetwinding 4 of the generator 3. T he generator will thus be caused toincrease the voltage of the circuit 1-2 to its normal value. if thevoltage of the circuit 1-2 increases, the contact terminal 3 will beraised correspondingly, because of the increased magnetization of thewinding 26, and the contact terminal 20 will then be required to move ashorter distance in order to engage the contact terminal 2?. I T 1eresult is, as will be understood from the "foregoing description, thatthe field excitation of the exeiter generator, and also that of the maingenerator 3 will be increased, and a corresponding decrease in thevoltage of the circuit l-2 will be thereby effected. A

In the system shown in Fig. 2-, only a single auxiliary field magnetwinding 28 is provided for the exciter generator, the said winding beingpreferably arranged to act in conjunction with the main winding (5, themagnetization afforded by which willbe somewhat less than is requiredfor normal operation.

If desired, however, the auxiliary winding J may be arranged to act inopposition to the main winding, as indicated in Fig. 3, and the flattermay afford a greater field magnetiza tion than is necessary for normaloperation. A resistance 29, that is connected'in series with theauxiliary winding 28, is shunted when the voltage of the circuit l-2rises above a predetermined value, by means of a device comprisingcooperating stationary and movable contact terminals 30 and 31',respectively; The latter terminal is carried by a pivoted arm 32 that isoperated against the tension of a spring 33 by means of anelectro-magnet having a winding 34, the circuit of which is governed bythe devices comprising levers 19 and 24, said levers being respectivelyresponsive, in operation, to the voltages of the eXciter and maincircuits. Thus, if. the auxiliary winding 28 acts in conjunction withthe main winding 6, and the voltage magnetization afforded winding 28and a corresponding decrease in the voltage of the exciter circuit.This, in turn, causes a weakening of the field of the generator 3 and adecrease in the voltage of the circuit 12', this voltage beingmaintained substantially constant in a manner which will be readilyunderstood from the foregoing description.

If the auxiliary winding 28 acts in o position to the main winding 6(see F ig. 3), the contact terminals 30 and 31 should be caused toengage when the voltage of the circuit 12 increases, in order to shuntthe resistance 29 and cause a decrease in the field strength of theexciter with a corres onding decrease in the field strength and V0 tageof the generator 3.

It follows that the invention provides means for maintaining asubstantially con-. stant voltage in a circuit supplied by adynamo-electric generator notwithstanding load variations or otherdisturbing conditions, and also that it is particularly applicable tosystems in which large exciter generators are employed, since thecircuit controlling deviees are traversed only by'the same amounts ofcurrent as traverse the auxiliary field magnet windings of the excitergenerator, which will ordinarily be small in amount as compared withthat which traverses the main field magnet winding.

In another application, Serial N 0. 325,291, filed by me July 9, 1906, Ihave described means for maintaining a substantially constant voltage ina circuit "supplied from any suitable main source and a storage battery,the operation of which is similar to that of the invention which formsthe subject-matter of the present application.

lclaini as my invention:

1. The combination with an electrical eircuit, and a dynamo-electricmachine con nected thereto, of an exciter generator having a main fieldmagnet winding and two auxiliary field magnet windings arranged to act:in 0 position, resistances in circuit with the res, active auxiliaryfield magnet windings and means responsive in operation to variations inthe voltage of said circuit for shunting the one or the other of theresist ances.

2. The combination with an electrical circuit, and adynamo-electrnmachine connested thereto, of an exciter generator havmg amainfield winding and two auxiliary field magnet windin s not inopposition, resistances 1.1 "ll/ll the respective auxiliary field magnetwindings and means responsive in operation to variations in the voltagesof said circuit and the excitcr circuit for shunting the one or theother of the resistances.

3. The combination with an electrical circuit, and a dynamo-electricmachine connected thereto, of an exciter generator having a main fieldmagnet winding and two auxiliary field magnet windings arranged to actin opposition, resistances in circuit with the respective auxiliaryfield magnet wind ings, and means for shunting the one or the other ofthe resistances comprising co-acting contact terminals that areresponsive in op eration, respectively, to variations in the voltages ofthe said circuit and the exciter circuit. A

4. The combination with an electrical circuit, and a. dynamo-electricmachine connected thereto, of an exciter generator having a main fieldmagnet-winding and two auxiliary field magnet windings arranged to' actin 0 position, and means for causing the one or t ie other of theauxiliary windings to act in conjunction with, the main winding.

5. The combination with an electrical circuit, and a dynamo-electricmachine eonnccted thereto, of an exciter generator hav:

or in opposition to,

ling a main field magnet winding and two auxiliary field magnet windin sarranged to act in opposition, and means f or causing the one or theother of the auxiliary windings to act in conjunction with, or inopposition to, the main winding, the saidmeans being responsive inoperation to variations in the voltages of said circuit and the exeitercircuit.

6. The combination with an electrical'circuit, and a dynamo-electricmachine connected thereto, of an exciter generator having a main fieldmagnet winding and two auxiliary field magnet windings connected to act,respectively, in conjunction with, and in opposition to, the mainWinding, and control switches governed by the main circuit and theexciter circuit voltages to vary the resistance of the circuit of theone or theother auxiliary field magnet winding.

7. The combination with a dynamo-electric machine, and an exciter forits field magnet having a main field magnet winding and two auxiliaryfield magnet windings that oppose each other, of a plurality ofinterdcpendent control switches that are governed by the main andexciter voltages to vary the resistance of the circuit of the one or theother auxiliary field magnet winding.

8. The combination with a main electrical circuit, and a dynamo-electricmachine connected thereto, of an exciter generator having field magnetwindings arranged to act in opposition, and means responsive inoperation to the voltages of the main and exciter eXciter circuits forshunting the resistances.

10. The combination with a main electrical circuit, and adynamo-electric machine connected thereto, of an excitcr generatorhaving iield magnet windings arranged to act in opposition, and meansfor adjusting the resistances of the circuits of the field magnetWimlings, the said means being responsive in operation to the voltagesof the main and eX citcr circuits.

l1. The combination with a main electrical circuit, and adynamo-elcctric machine connected thereto, of an exciter generatorhaving field magnet windings arranged to act in opposition, and meansfor adjusting the resistances of the circuits of the field magnetwindings so as to maintain the voltage of the main circuit substantiallyconstant.

12. The combination with a main electrical circuit, and adynamo-electric machine connected thereto, of an exciter generatorhaving field magnet windings arranged to act i in opposition, and meansfor adjusting the resistances of the circuits ofthe field magnetwindings, the said means being responsive in operation to the voltage ofthe main circuit.

13. The combination With a main electrical circuit, and adynamo-electric machine connected thereto, of an exciter generatorhaving field magnet windings arranged to act in opposition, and meansfor adjusting the re- "sistances of the circuits of the field magnetwindings, the said means bein responsive in operation to the voltage oft 1e exciter circuit.

In testimony whereof, I have hereunto sub- FRANK CONRAD. Witnesses:

OTTO S. SoHArRER,

BI'RNEY HINEs.

scribed my name this 29th day of December,

